Re: System username in pg_stat_activity

Hi,

On Thu, Jan 18, 2024 at 04:01:33PM +0100, Magnus Hagander wrote:
> On Mon, Jan 15, 2024 at 11:17 AM Bertrand Drouvot
> > Did you forget to share the new revision (aka v4)? I can only see the
> > "reorder_parallel_worker_bestart.patch" attached.
>
> I did. Here it is, and also including that suggested docs fix as well
> as a rebase on current master.
>

Thanks!

Just a few comments:

1 ===

+ The authentication method used for authenticating the connection, or
+ NULL for background processes.

What about? "NULL for background processes (except for parallel workers which
inherit this information from their leader process)"

2 ===

+ cycle before they were assigned a database role. Contains the same
+ value as the identity part in <xref linkend="system-user" />, or NULL
+ for background processes.

Same comment about parallel workers.

3 ===

+# pg_stat_activity should contain trust and empty string for trust auth
+$res = $node->safe_psql(
+ 'postgres',
+ "SELECT auth_method, auth_identity='' FROM pg_stat_activity WHERE pid=pg_backend_pid()",
+ connstr => "user=scram_role");
+is($res, 'trust|t', 'Users with trust authentication should show correctly in pg_stat_activity');
+
+# pg_stat_activity should contain NULL for auth of background processes
+# (test is a bit out of place here, but this is where the other pg_stat_activity.auth* tests are)
+$res = $node->safe_psql(
+ 'postgres',
+ "SELECT auth_method IS NULL, auth_identity IS NULL FROM pg_stat_activity WHERE backend_type='checkpointer'",
+);
+is($res, 't|t', 'Background processes should show NULL for auth in pg_stat_activity');

What do you think about testing the parallel workers cases too? (I'm not 100%
sure it's worth the extra complexity though).

Apart from those 3, it looks good to me.

Regards,

--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com